Abrasive tool



Nov. 29 1949 s. w. ALLRED 2,489,250

ABRASIVE T001:

Original Filed May 21, 1947 I N VEN TOR.

Patented Nov. 29, 1949 UNITED STATES PATENT OFFICE Divided and this application January 31, 1949, Serial No. 73,835

1 Claim.

This invention relates to an abrasive tool comprising sandpaper, emery paper, emery cloth or the like, i. e. any suitable flexible support such as paper or cloth provided with an adhesively attached coating of abrasive grains or powder such as sand, emery or the like.

The invention resides primarily in an abrasive strip which may be in the form of a continuous multi-layer belt or in the form of a multi-layer pad, or in the form of a wheel or drum. The abrasive strip consists essentially of the abrasive and its adhesively attached flexible support which for convenience will be referred to hereinafter as sandpaper, and means for adhesively attaching successive layers of the strip to each other without applying the adhesive to the abrasive surface.

An object of the invention is to provide an adhesive strip construction which, when wound around a rotatable shaft to form a wheel and rotated as is customary in the use of abrasive wheels, will be flexible or soft to the object being sanded due to the expansion of the strip by centrifugal force.

A further object of the invention is to provide an abrasive strip construction which readily can be varied by simple adjustment of the tape folding mechanism in which the strip is formed so as to produce a strip that when wound to form a wheel will give a wheel of any desired degree of softness.

Other objects and advantages of the invention will appear in the following detailed description of the several illustrative embodiments shown in the accompanying drawings in which:

Fig. 1 is a front elevation of a sandpaper wheel, and

Fig. 2 is a greatly enlarged cross-section of several layers of the abrasive strip construction.

Referring to Fig. 1, l is the rotatable axle which carries the sleeve 2 secured thereto by means of the set screw 3, the fixed flange 4 and the adjustable flange 5 which is positioned by the nut 6 screw-threaded on the sleeve 2. The parts 1 to 6 constitute a spool for mounting the abrasive wheels.

Tools generally are formed from the strip by winding a continuous strip either around a core or tube to-form a wheel or around a removable support to form a continuous belt which may be cut into sections of the desired length to form pads. It is, however, within the scope of my invention to form a wheel, belt or pad by superposing successive parallel layers. In any event,

the superposed layers must be attached to each other in such a way that each layer, when it becomes worn, may be detached to expose the next layer for use. In Fig. 2, 1 represents a base or core to which the successive layers are attached, 8 is the flexible strip of paper or the like, and 9 is the adhesively attached layer of abrasive. The first layer of the flexible support is glued to the base I. For attaching successive layers the support 8 is provided with integral edge portions 26 which are turned in and adhesively attached to the back of the next layer of the support 8. As is apparent the edge portions 26 may be folded more or less loosely so as to provide for more or less expansion between the successive layers under the influence of centrifugal force and thus give a more or less soft wheel. II is a protecting strip of paper or the like which overlies the abrasive 9 and protects it from accidental application of adhesive to the abrasive when the successive layers are being adhesively attached.

It is noted that the edge portions 26 are of sufficient width only to provide for the desired separation of the layers and for adhesive attachment of each layer to the next layer. This serves two purposes: (1) to save the material of the support as compared with a construction in which the edge portions 26 extend entirely across the strip, and (2) to leave a space between the protecting strip ll of one layer and the back of the support 8 of the next layer, this space serving to make the tool soft whether it is being used in the form of a wheel in which centrifugal force tends to induce a separation of the layers or in the form of a belt or pad in which the softness must be inherent in the tool without the intervention of centrifugal force.

The successive layers are secured together as indicated above by gluing the edge portions 26 of each layer to the back of the support of the next layer, the strip ll serving to protect the abrasive coating 9.

In use when the top layer becomes worn it is removed by tearing the edge portions 26 and removing the strip ll thereby exposing a fresh abrasive surface.

It is obvious that the protecting strip H may be omitted provided that care is taken in gluing the successive layers together to avoid getting adhesive on the abrasive surface.

This application is a division of my application Serial No. 749,497 filed May 21, 1947.

I claim:

An abrasive tool comprising a plurality of 3 superposed. layers, said layers each comprising a flexible support having on at least a portion of one surface thereof an adhesively attached coating of abrasive material, and flexible integral attaching strips extending from adjacent each edge of the abrasive coated portion of said support around the edges of said abrasive coating and over at least a part of the free surface thereof and adhesively attached to the back of the next superposed layer, the width of that portion of 10 each attaching strip extending around the edge of the abrasive coating between the edge of the No references cited. 

